The 1970s. Too little is written about the mechanics of the genre at that time. This collection is short bios and essays by well-regarded writers of the past. Regardless of whether I liked the outputs of the writers, I found this good, informative stuff. There were six contributors. For the benefit of readers of today, with the hindsight of many years, I have included (in parentheses) a representative work. Go check out SF writing as it was.

As was the case back then, SF writers of today are often too busy ploughing their own furrows, nevertheless I would also recommend this to any who have an interest in writing beyond simply cranking out product.